Air Carbon for Algae Production (AirCAP) – Expanding algae resource potential via direct (in-pond) air-CO2 capture.

Conference · Mon Jun 17 04:00:00 EDT 2024

DOI:https://doi.org/10.2172/2440050· OSTI ID:2440050

Crowe, Braden ^[1]; Greer, Mattias ^[2]; Benemann, John ^[2]; Gao, Song ^[3]; Edmundson, Scott ^[3]; Huesemann, Michael ^[3]; Nalley, Jakob ^[4]; White, Rebecca ^[4]

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1. MicroBio Engineering, Inc., 3988 Short St #100, San Luis Obispo, CA 93401-7574, USA; MicroBio Engineering, Inc.
2. MicroBio Engineering, Inc.
3. Pacific Northwest National Laboratory (PNNL), Sequim, WA (United States)
4. Qualitas Health

Microalgae biofuel production potential in the United States is constrained by a lack of suitable cultivation locations within a close proximity to CO2 point-sources. Initial estimates suggest that removing the requirement of a concentrated CO2 source expands resource potential ten-fold, allowing the projection of production levels that approach levels of current U.S. diesel consumption. Decoupling cultivation locations from concentrated CO2 point-sources requires direct capture of air-CO2 into the pond bulk at a rate sufficient to meet maximum expected carbon assimilation rates (10 g C/m2-day and higher). Enhancement of the ingassing rate via chemical reaction, the direct reaction of dissolved CO2 with hydroxide ions, has been proposed as a mechanism to increase the ingassing rate of air-CO2. The central objectives of this project are to validate whether chemically enhanced air-CO2 ingassing rates in large raceway ponds can meet or exceed the level required to support high levels of algae productivity, then subsequently identify alkaliphilic strains able to withstand such conditions while maintaining a biomass productivity that enables process economics. Full scale ponds (~1 acre, unlined) will be used to validate ingassing rates as a function of pH expected at scale in a series of abiotic experiments. To date, mass-transfer dynamics have been characterized in ponds ranging from 1 to 1,000 m2. Initial results will be presented describing the mass transfer coefficient in 1-acre (~4,000 m2), unlined ponds. The maximum expected carbon ingassing rate will be measured during ingassing trials, in which pond pH is displaced from equilibrium via the addition of a strong base, with the subsequent decrease in pH (and increase in dissolved inorganic carbon) corresponding to the air-CO2 absorption rate. A mass-transfer model, validated with experimental results, will be used to project ingassing rates expected at pond scales (10 acres) required for production of commodity chemicals.

• Research Organization: MicroBio Engineering Inc
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: EE0008519
• OSTI ID: 2440050
• Report Number(s): DOE-MBE-8519-01
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
AirCap
algae
CO2 Air Capture